| improbable(adjective, uncertain, doubtful, shaky, unsure) |
| inconclusive(adjective, clear, obscure, certain, uncertain) |
| open(adjective, uncertain, doubtful, unsettled, shaky) |
| unlikely(adjective, uncertain, doubtful, shaky, unsure) |
| arguable(adjective, uncertain, doubtful, unsettled, dubious) |
| chancy(adjective, clear, certain, uncertain, doubtful) |
| clouded(adjective, clear, obscure, certain, uncertain) |
| doubtable(adjective, uncertain, doubtful, shaky, unclear) |
| implausible(adjective, improbable) |
| incredible(adjective, improbable) |
| indeterminate(adjective, clear, certain, uncertain, doubtful) |
| moot(adjective, uncertain, doubtful, unsettled, dubious) |
| unclear(adjective, clear, obscure, certain, uncertain) |
| unsettled(adjective, uncertain, doubtful, vague, dubious) |
| at issue(adjective, idiom, clear, certain) |
| in doubt(expression, adjective, idiom, clear, obscure) |
| speculative(uncertain, shaky, unclear, unlikely, questionable) |
| unpromising(shaky, unlikely) |
| absurd |
| beyond belief |